'WORLD HEALTH DAY 2013' - Hypertention Feeling The Pressure

A raised BP reading may not always be an indicator of hypertension. Sometimes it could just be the ‘white-coat effect’ playing havoc, making diagnosis tricky. Diagnosing hypertension would seem the easiest task in medicine. Get strapped to a simple sphygmomanometer and the diagnosis is ready in the few seconds that it takes the heart to beat out a lub-dub tune. 
    
But India’s hypertension story—with over 139 million patients at a conservative estimate—is far from simple. On the one hand, experts warn of a silent epidemic in which people, especially those in rural areas, fail to get diagnosed before some organ failure sets in. The World Health Organisation has, in fact, dedicated this ye a r ’s Wo rl d Health Day to the perils of untreated hypertension on one’s heart, kidneys and brain. On the other hand, there is the human element—a sudden burst of self-concern at seeing the doctor wearing a white coat — that sends blood pressure soaring. 
    
While a lot has been written about underdiagnosis of hypertension, it is only recently that the medical fraternity has begun vocalising the perils of overdiagnosis and overmedication. The reaction to the white coat—awarded a medical nomenclature as the ‘white-coat effect’—creates a huge increase in BP readings. “Many patients will have high blood pressure when visiting their doctor’s office,’’ says Dr Anoop Misra, who heads the department of diabetes and metabolic diseases in Fortis Hospitals, Delhi. Endocrinologist Shashank Joshi from Mumbai’s Lilavati Hospital says almost 30% of the patients who walk into a doctor’s clinic would suffer from the white-coat effect. 
    

A team from Duke University in the US studied the phenomenon in the management of hypertension. In the study, published in the Annals of Internal Medicine, BP readings taken in doctors’ offices were consistently higher than those taken at home or in a research setting. The study concluded that the white-coat effect was responsible for patient overtreatment. 
    
In India where one in five (and in some cities, one in four) adults is supposed to be suffering from hypertension and taking pills, there is a need to weed out the white-coat effect. “Pilots often have a higher BP reading at their aviation company doctor’s clinic. But when they are sent to us for a re-evaluation, the pressure is lower,’’ says cardiologist Ganesh Kumar with L H Hiranandani Hospital in Mumbai. The same is the case with people appearing for preemployment health checks. 
    
Why does the white coat affect blood pressure so much? People are anxious about their health when they go to a doctor’s clinic, placing an unrealistic emphasis on the white coat. Dr Joshi calls it a biochemical reaction: “Stress and anxiety lead to a rise in catecholamines (hormones released by adrenal gland in times of stress) which, in turn, leads to an increase in BP.’’ 
    
However, this can be easily neutralised. Dr Misra says persons should be asked to sit quietly for at least five minutes in a chair with their feet on the floor and arms supported at heart level. “Caffeine, exercise and smoking should be avoided at least 30 minutes prior to the measurement,’’ he adds. 
    
The medical advice now is to have at least two-three BP readings before ruling that the pressure is indeed high and starting medication. “The only exception would be if the patient’s first-visit BP is very high,’’ says Dr Misra. 
    
The Duke University study had, in fact, said that repeated measurements should be taken at home to get an accurate picture of BP control than a single reading in a doctor's office. “In fact, we now order an ambulatory blood pressure reading for some patients,’’ points out Dr Joshi. The patient has to walk around with a tiny machine that records various readings over a 24-hour period.